Toxic gas monitoring: Trends, training, and safety
04/01/1997
Toxic gas monitoring: Trends, training, and safety
Lorraine Savage, Associate Editor
A recent focus group on toxic gas monitoring promoted discussion of important industry issues. The forum, sponsored by Zellweger Analytics Inc. (producers of the MDA series of toxic gas monitoring systems) and moderated by Solid State Technology, highlighted concern for safety standards, fire code compliance, bulk delivery, training, and network standardization (see table).
Safety. Manufacturers agree that safety is of utmost importance. However, making a product that satisfies all fire codes is difficult, because fire codes differ from community to community and are subjectively interpreted by the fire official making the inspection. "This leads to problems in the engineering process," said Drew Deichmann, western regional sales manager of Zellweger. "There has been an effort by a few agencies to standardize code issues. There`s been limited success on that, but the biggest problem comes from local communities in Silicon Valley." He said that there are significant code differences within Silicon Valley: Palo Alto, Mountain View, Sunnyvale, and San Jose all differ. Moreover, while the Uniform Fire Code and Toxic Gas Ordinance are used on the West Coast and other codes are used only west of the Mississippi, the East Coast has NFPA and BOCA codes, while the South has SBOC codes.
To further complicate matters, the Uniform Fire Code is revised every three years, and amendments are made in the interim two years. Even municipalities that operate under the Code haven`t necessarily adopted the revisions or amendments and operate under older versions. Joe Hill, director of quality and safety at Air Liquide, Walnut Creek, CA, a maker of gas distribution systems, noted, "A publication from the Semiconductor Industry Organization indicated that there was an effort to consolidate all the codes across the country, such as the BOCA and Uniform Codes. From my experience, the various organizations that sponsor these codes and have authorship of them may not want to relinquish control."
From the buyer`s point of view, David Ham, manager of environmental health and safety at the Xerox Palo Alto Research Center, agrees with this problem of differing fire codes. "We have the manufacturer meet our standards for the state of California," he said, "but sometimes this isn`t possible. The profit margin on some equipment is so slim, that if the manufacturer makes the requested modifications, it`ll quadruple the cost." Whether to modify onsite, for Ham, is a question of critical life safety. "You might not want to modify a toxic gas monitor that monitors arsine, but you might agree to modify your own monitor of hydrogen. [The decision] is based on the safety level."
Ham noted that vendors, "clearly need to understand if the user is going to use SEMI standards or OSHA regulations." There is an ongoing effort to develop uniform standards for use across the US. "I applaud that effort because it`s well overdue," said Ham. "A lot of that is being driven by the fire chiefs` associations. They are a strong lobbying group. They`re supposedly coming up with something by 2000."
One improvement that has been suggested for manufacturers is to build a toxic gas monitoring system directly into their equipment, and not require end-users to add it on later. Ham noted, "When manufacturers make equipment that uses a toxic gas, they do not build it with the monitoring part in mind. [They should] build these safety features into their equipment from the very beginning. After the [toxic gas monitoring] forum, I received a few calls from MDA, who said that they`re going to start pursuing these ideas. I think that`s a wonderful thing to do."
Zellweger`s Deichmann added, "The safety monitoring devices in and of themselves are part of a larger system called the Life Safety System." He explained that a variety of inputs, in addition to toxic gas monitoring, such as seismic monitoring, fire detection, and manual pull stations, all feed into this larger Life Safety System. This system in turn automatically shuts off cylinder gases and autodials the fire department. "They all dovetail together," he said.
Safety should be considered not only after the equipment is installed, but also before the equipment is purchased. One problem noted by Chris Brown, technical sales manager at ENMET Corp., a gas handling and monitoring company in Ann Arbor, MI, is that customers sometimes don`t know what they need. He added that many products sold today are not being totally utilized in the manner for which they were designed. Brown explained that customers assume that they need a detector for carbon monoxide, hydrogen sulfide, methane, and oxygen - four of the five most common killers in confined spaces, when they really need monitors for the toxics, oxygen, and combustibles for their specific type of space. "People end up buying something because it`s well marketed, but that may or may not cover the gases that are appropriate for their use. Most products can`t be reconfigured in the field," said Brown. He said that ENMET tries to equip its distributors and sales reps with specific questions to ask consumers to determine the appropriate monitoring system for their needs.
Bulk gas delivery. A controversial subject in the toxic gas industry is bulk gas delivery of some products that are used in larger quantities, such as silane. Bulk chemical delivery affords certain advantages, such as less equipment cost, and better purity due to less frequent cylinder changeout. "Every time you connect and disconnect, you have to go through purge cycles to maintain a clean system," noted Air Liquide`s Hill. He explained that if a bulk supply of gas lasts half a year or one year, there is more consistency of product going into processes. There are also fewer chances to involve the human element when cylinders need to be changed. "If you hook it up once a year, rather than once a week, you`ve reduced the number of times a person could make a mistake."
Ham agreed, but noted that with a procedure performed only once a year, the chances of error increase if workers get complacent. His solution: "If you have good procedures in place and people are made to follow those procedures, the complacency issues are extremely low. It`s when you don`t follow a standard written procedure and you don`t have a checklist
method of going through it that people do become complacent."
Other disadvantages of bulk delivery are obvious. "The downside is that silane is a pyrophoric material. There`s concern that a large number of facilities are built in areas that are not totally isolated from a general populace," said Hill. Deichmann concurred. "If you have an accident, the magnitude is multiplied 500 times." The concern is whether individual communities are willing to accept larger tanker trucks full of chemicals without significant concern. Deichmann commented, "We found that some states in the Southwest, like Arizona and New Mexico, were a little more open to, and perhaps unaware of, bulk chemical dispensing going on in their regions."
Training. Training has been an important area of concern for manufacturers and users in the toxic gas monitoring industry. Forum participants agreed that employee confidence in toxic gas detection systems, and safety procedures in general, can only be achieved by regular, repeated training. "A well-educated employee is a better employee because he can understand the hazards and risks and take more care in his job," said Deichmann. "And if problems occur, he`ll be better trained to deal with them at that time."
Xerox`s Ham noted one hitch in the training process. He observed that companies can`t train in live situations, meaning that they can`t cause an extremely toxic gas to leak just so they can train employees how to shut it off. "We need to find a gray area where we can simulate accidents a lot better than what we are currently doing."
Most companies have response teams that deal with emergency situations when they arise. To improve employee confidence in monitoring systems, forum attendees recommended that toxic gas detection systems should always be in view, and alarm levels, indicators, and exit procedures should be clear to all employees. In addition, increased emphasis on training, knowledge, and communication is needed.
Suppliers must also train users of their equipment, which is difficult if customers experience high turnover of employees. ENMET`s Brown said, "We encourage our distributors and sales reps to perform training with the customer with every product. And we offer our customers training videos, which are particularly useful if they have a high employee turnover."
Networks. Among the new trends in the industry is the growing importance of networks. DeviceNet is a standard for digital communications within a system and possibly between tools as well. This protocol determines how machines or devices talk to one another, and goes further to define stop bits and parity. Ed Korczynski, Solid State Technology`s West Coast editor and forum co-moderator, explained, "It`s important to the whole issue of integrating sensors, including toxic gas monitors, and subsystems within a tool. There have been other proposed standards, and political industry in-fighting has prevented an official standard for over three years. Recently, Applied Materials announced that its next major system platform will be built with DeviceNet; in effect, forcing it through as a standard." Deichmann agreed, "Applied is the proverbial 800-pound gorilla. If they are driving DeviceNet as a communications standard, most if not all of the industry will follow so they can communicate with different platforms."